Addition of 2-phenyleth-1-ylamine (from the hydrochloride salt and triethylamine) to 4-[[3-[[2,6-bis-[1,1-dimethylethyl]thio-4H-pyran-4-ylidene]methyl]-2-methoxy-4-oxo-2-cyclobuten-1-ylidene]methyl]-2,6-bis[1,1-dimethylethyl]thiopyrylium tetrafluoroborate using conditions analogous to those of Example 52, Part B above provides the dye N (FIG. 3 ) in which R3 is a 2-phenyleth-1-ylamino group and R1